According to national mortality data, Hispanics appear to live longer than other persons do in the United States. In addition, recent studies indicate that immigrants, regardless of ethnicity, also experience enhanced longevity in the United States. The goal of this project is to examine the quality of data that may be influencing these advantages in mortality. If Hispanic ethnicity or foreign-born status is miscoded on death certificates, mortality rates may be artificially deflated for these populations. Several independent data sources, including both publicly available nationally-representative survey data and record-linkage data, will be examined to assess how much of these differentials are due to poor data quality, and how much is a true advantage. This pilot project is designed to lead to an R01 grant that might examine explanatory factors behind the advantage sometimes referred to as the "Hispanic paradox". However, without understanding the level of error in the data (and thus, how large the advantage truly is), it is premature to move forward to examine possible causal mechanisms. Five independent data sources will be utilized in this research: the Health and Retirement Study (HRS), the Assets and Health Dynamics of the Oldest Old (AHEAD), the National Health Interview Survey-National Death Index Linked File (NHIS-NDI), the San Francisco-Oakland area study by the Northern California Cancer Center, the National Mortality Follow-Back Survey of 1993, and the complete vital statistics of the United States matched with population estimates from the 1990 census.